Introduction

The Irish grain yield can regularly be stored for up to a year after harvest before processing. During this period the grain can deteriorate in the store due to natural decay and insect infestations. This deterioration is hastened by the initial temperature being too high. Once infestation starts, the temperature continues to rise ever more quickly. The higher the temperature rises, the more the insect infestation and grain deterioration is magnified and can result in the entire crop being lost.

Until now, continuous temperature measurement has been a time-consuming chore which requires regular checks to ensure accurate readings. Using Sigfox devices for temperature monitoring reduces cost of deployment, cuts the farmer’s time spent overseeing the sensors, and ensures clear information is readily available in a straight-forward graphical display.

Fluctuating grain silo temperatures is a common problem for farmers. Monahan farms traditionally dealt with this by monitoring the grain temperature from the beginning of the storage period and blowing cool air through the grain when the temperature started to rise. A rise in temperature indicates a developing insect problem. If discovered in time, blowing cool air through the grain can solve the problem before it becomes established. This case outlines how VT/Sigfox devices have helped to achieve this.

The Challenge

Laborious and time-consuming temperature checks must be done regularly to prevent expensive infestations. Furthermore, grain quality assurance schemes are becoming increasingly common as a standard in grain production. These schemes demand detailed information about the production and storage of farmers’ crops. Temperature readings are required in order to prove the grain has been stored properly and that the temperature never rose above certain thresholds. This quality assurance is expected to become mandatory in the near future.

Monahan farms had been looking for a simple and cheap method of remotely monitoring the temperature in the grain. Some of the meters they were using gave readings, but were costly and the information they provided was not compiled in any useful way, so no trends could be acted on. The information coming from the sensors needed to be available as a graph on a computer or phone application and downloadable for use in a spreadsheet.  The temperature changes in the grain are slow, so it would only be necessary to report the temperature a few times a day. A rise in temperature over a few days or a week, preferably shown in graphs, would indicate a problem.

The Solution

Sigfox devices looked like an easy solution as they have a long battery life and do not require any sort of wired or Wi-Fi connection. After consulting with VT, Michael Monahan, of Monahan Farms, installed a Linobjec sensor in his grain silo and saw immediate results.

It has two sensors: one in the unit itself and another at the end of the attached two-metre cable. It signals the temperature every half hour. The attached probe reports the temperature from two metres down in the grain, which is contrasted to the air temperature above it.

As each module is battery equipped with a minimum lifetime of two years, it is very simple to install and simply read the data received on the application.  The Linobjec sensor has an operating temperature in range of -50 ° to +90 ° and a tolerance of +/- 0.5%. There are cable lengths of up to two metres available.

Michael is now able to view all the data on the web application, which is also transferred to the website for secure archiving. Each of the temperature results can be combined to show long-term trends on easy to access reports, which can then be retrieved in PDF or CSV (Excel) formatting.